The mind-bending quantum world

Kavan Modi – Physicist

Have you ever thought of your computer as a ‘classical’ device – a machine with processor signals that are simply either turned on or off? If you tell it to do one thing, it will do it. Tell it to do another and it will respond a different way. It seems strange to think of your device as classical, with the implication that it’s ‘old-school’.

Perhaps you’d prefer a ‘quantum’ computer? What if it could offer more than simply one or two solutions – but rather offer both simultaneously. Multiply this notion thousands of times and your shiny new computer would offer you hundreds of thousands of solutions – good, bad and the very best – in lightning fast time.

As a quantum physicist, I am not interested in nature’s construction but I am interested in the logic that nature follows. I guess the world of quantum devices was dreamt up 30 years ago and it’s worth remembering that no one has ever managed to do an experiment that surpasses what nature achieves. I am focussed on finding something we can achieve – somewhere in the middle – between classical and quantum. A little bit of both at the same time. My goal is not purely profit-driven. I hope my research will one day have an impact on harvesting energy, designing green chemicals and ways to eliminate carbon-based fuels. It could be a savior for us all.

We are on the threshold of major change. Yes, we have witnessed extraordinary progress in the last 70 years – with smart phones, processors and other devices that have, roughly, become twice as fast and half the size every two years or so. Computers that have, for example, turned the labour of Mickey Mouse cartoon animation into a spectacular art form where Dreamworks now produces half a billion frames per film. We have managed this enormous advance due to our capacity to design machines that process information.

But we have almost reached a stopping point. In 20 years, we will hit a wall. Microprocessors built from silicon transistors will no longer be made smaller and faster because we will reach a limit. When transistors become so small that they are only made of a few atoms they obey quantum laws. We must learn to work with such devices or we will cease to make better computers. Thankfully quantum computers will enable us to solve problems with surprising speed.

And this is where the quantum world comes into its own. It will allow us to answer questions as never before. I would go as far as to say building this type of computational power will be as important as our need to solve global warming.

The quantum world challenges our natural instincts. In the classic world, a flash-light is turned on or off. In the quantum world, it can be on and off simultaneously. In the quantum world, it could be. In fact, you could multiply this and have many options, myriad solutions. Not all would be good but you could pick-out the best.

All over the world, money is being invested in quantum mechanics as we make the transition from classical to quantum. Defence agencies, government departments and companies using materials science and building computers, like Toshiba and IBM, are investing. Singapore, Canada and the United States are leading the charge. Australia is big in this field, with other groups in QLD and NSW.

Quantum computers will revolutionise security authentication and will speed-up our understanding of the property of materials. While we never would’ve predicted the Internet in the 1970s, we still don’t know what we’ll be able to do in 40 years’ time. But I would take a stab and say we’ll all be using a hybrid device that runs a quantum computer that checks-in with a classical computer because, at the end of the day, it’s easier to check and answer than to find a new one.

Dr Kavan Modi recently joined the School of Physics at Monash University and is soon to welcome another student to join two already on the ground. Kavan has come from University of Oxford in the UK and Centre for Quantum Technologies in Singapore and is first to work in the field of quantum information theory at Monash.

Quantum computers will revolutionise security authentication and will speed-up our understanding of the property of materials. While we never would’ve predicted the Internet in the 1970s, we still don’t know what we’ll be able to do in 40 years’ time.